Wax dental form and method of making same



Feb. 7, 1933. sc w n-z 1,896,123

WAX.DENTAL FORM AND METHOD OF MAKING SAME Original Filed July 29, 1925Even/'0)" Patented Feb. 7, 1933 UNITED STATES HEINRICH scnwiiri zan. ormiw Yoax; 1

Wax DENTAL Foam m 'unrrnon so: Mame. mm

ori inal: a ncetionm d July 29,;1925, swarm, 46, 757- n med and thisapplica tlon filed June'18..

1928. Serial- NO- 285,075.

The invention relates in general to ameth- 0d of manufacturing, dentalpatterns .and

forms, such as ba'ckings, sprue forms, shells and crowns, when made ofdentalwax or 6 similar moldable. material and the present" applicationconstitutes a division of. my pending application Serial, No.46,757filed.

Juy. 29, 1925. I 0

rms and patterns this character. are

10 usually'made from a composition of beeswax,

" rosin, paraflin and-other soluble bodies and v are made of twodegreesof hardness or rigid.- ity,.one type generally known assoftdental wax having a higher percentage of beeswax than the. othertypeidentifiedas hard. dental wax. Y p g The a use: of soft dental formaking such forms has certain advantages for the forms made'therefromarepliable at normal room temperatures; they do not break easily; theyare adhesive and sticky, but are not very rigid. The formers made fromthe hard dental wax have the advantage in that they are easily curvedupon the surface and while they .25 are brittle, they are also rigid atnormal temperature; do not bend and are non-adhesive.

The primaryobject of the present invention is to provide a simple methodfor manufacturing a dental form which will combine in one article all ofthe advantages inherent in such articles when made heretofore separatelyof hard and soft dental waxes.

Broadly, I attain this phase of the inven .35 tion by forming a shell ofsoftwax and imposing thereon a similar thin shell of hard wax andpermitting the same to adhere integrally to form a shell of the desiredcon-.

1 figuration. 0' Various other objects and advanta es of the inventionwill be in part obvious mm a consideration of the method features of thedisclosure and from an inspection of the accompanying drawing, and inpart will be l more fully set forth in the following particpracticed andillustrating: in axial section one There will-be 'left'in the mold anextremely Renewedil'une 20, 1982,

certain newfa nd. novel modifications of the f preferred methods andother features of construction and .-combination of parts hereinafterset forth and claimed.

physical embodiment of the article feature of the disclosure Figure 2isva View in side elevation of a male mold showing formed thereinanother embodiment-of the article feature of the disclosure; and I 1"Figure 3 is aview partlyin side elevation and partly in section offawaxiform con. stituting a modification of the form shown. in Figure 1'.we I In the following description and in the claims, parts will beidentified by specific names for convenience of expression but they areintended to be as generic in their application to similar parts astheart will permit. In the drawing and referring particularly to Figurelthere is shown a, multi section crown tooth mold' lO of conventionalconfiguration having a cavity 11 of the configuration desiredof thefinal wax form and which mold will be referred to specificallyhereinafter as af'emale mold in order to' distinguish from thecylindrical. plunger l2'constituting aniale form for forming cylindricalshaped. waxcrowns as shown in Figure 2. y The wax form. herein featuredmay :be formed following either one of two methods. Biy the'first methodthe wall 14 of the cavity is; wetted and liquid soft wax is introducedinto the cavity completely filling the" same 90 and immediately the moldis inverted so as to pour therefrom all of the fluid wax which has notin the meantime adherred to and crystallized on the outlining wall 14 ofthe cavity.

thin,- soft,. set wax layer 15, There is then introduced into the cavity111or rather into the space, formed by the shell forming layer 15,llquefied hard" wax again filling the'cavi and again the liquid wax ispromptly poure from the mold. This leaves an inner hard wax layer 16adherring to and integrally connected to the outer soft wax layer 15.The parts of the molds are separated and the form removed. There is thusproduced a thin wall two-layer wax shell with the layers havingdifferent degrees of hardness. It is obviously within the scope of thedisclosure to multiply the number of layers preferably alternating withsoft and hard wax so that there is eventually formedaumulti-la-yer.wax'shell of any degree of thickness. The thickness of each layer iscontrolled by the composition of the wax, by the temperature'of the sameand by the speed at which the operator works in introducing anddischarging the wax.

By the second method it is suggested that the male mold 12 previously,wetted, be dipped first into apool of liquidhard wax to form an innerhard wax layer 16, promptly withdrawn from the same to permit thesurplus wax to drain therefrom; after which the coatedimoldis fdippedinto a'pool of .liquidsoft wax, promptly withdrawn and drained. In theillustrated case the male mold is cylindrical so' that the resultingshell will .be of the conventional closed end. cylinder form and differsfrom" the conventional form in that it includes two layers of wax, thehard inner layer 16 and a soft outer layer 15. The shell thus formed canbe inserted into a mold of the type shown in Figure land by'fluid'ipressure exerted on the interior of the shell, it can beexpanded into engagement with the, wall 14 so as to take theconfigurationof the cavity fo'rmedfby suchwall Instead of coating allparts of the shell unis formly with its succeeding layers of soft andhard wax certain localizedp'ortions mayreceive an extra layer of eitherform ofwax and as one illustration of such modification reference ismade to Figure 3 where a limited amount of hard wax is introduced toform an additional layer 17 which is confined to the cusp portion of thetooth and thus provides an extra strong-reinforcement for this portionof the tooth.

the outlining wall of the mold, pouring into the wax shell so formed andwhile retained in the mold, a second filling comprising a hard liquidwax, thereby to cause the two wax layers to adhere to and integrallyconnect each other, promptly removing all hard wax not adhering to thefirst soft wax shell and removing from the mold the composite twolayershell so formed.

2. In the art of forming wax dental forms, the method which consists inwetting the wall of the cavity in a mold, filling the same with liquidsoft wax, and immediatelyv ouring from the mold cavity all the wax whichwill flow therefrom, leaving a soft thin wax shell in contact with theoutlining wall of the mold, pouring into the wax shell so formed andwhile retained in the mold, a second filling comprising a hard liquidwax, thereby to causejthe two wax layers to adhere to and integrallyconnect each other, promptly removing all hard wax not adhering to thefirst soft wax shell introducing into the bottom of the second cient tocover the bottom of said second filling but not suflicient to fill theshell formed by said second filling, thereby to provide a localreinforcement to the cusp portion of-the completed shell and removingfrom the mold the composite multi-layer shell so formed.-

Signed at New York in the county of New York and State of New York this6th day ofMarch AzD. 1928. i

HEINRICH SCHWEITZER.

filling an amount of wax sufli- V While I have shown and described, andI out departing from the spirit of the inven- V tion.

I claim :7 l i 1. In the art of forming wax dental forms,

the method which consists in" wetting the wall of the cavity in ,a mold,filling the same with liquid soft wax, and immediately pouring from themold cavity all the wax which. will flow therefrom, leaving a soft thinwax shell in contact with

